1. Field of the Invention
The present invention relates to differential mechanism restricting devices.
2. Description of Related Art
A differential gear is a device that generates a difference in rotational speed between left and right wheels. Depending on a traveling state, it is not necessary to a rotational speed difference between left and right wheels. In such a case, a differential mechanism restricting device is attached to a differential gear. Various proposals have been made with respect to a differential gear provided with a differential mechanism restricting device (see JP-A-2011-117511 (FIG. 3), for example).
As shown in FIG. 3 of JP-A-2011-117511, a fork member (74) (numerals with a parenthesis indicating symbols described in JP-A-2011-117511, the same being applied for the explanation made hereinafter) is swung by a lever member (75) indicated by an imaginary line, and a lock pin (70) is inserted into pin holes (71 and 72) by the fork member (74). Due to such a construction, an output-side cam (66) is integrally mounted on a ring gear (48) so that a differential lock state is completed. That is, switching of a drive mode by switching between a locked state and an unlocked state in a differential gear is performed by operating the lever member (75) using an operation element.
In addition to locking the differential gear during traveling, there has been a demand for bringing a differential gear into a locked state during parking. In an attempt to mechanically provide a differential locking mechanism (differential mechanism restricting device) for two usages without using an electric actuator, it is necessary to provide an operation element and a differential mechanism restricting device that perform differential locking for parking in addition to an operation element and a differential mechanism restricting device provided for changing over a drive mode.
As a result, the differential mechanism restricting device that is operated independently by two operation elements becomes large in size leading to an increased size of the differential gear and an increased vehicle weight.
As a result, there is a need for a miniaturized differential mechanism restricting device that is mechanically connected to two operation elements, especially in instances in which a reduced vehicle weight is desired.